Widespread male-female expression imbalance of X-linked genes across phrynosomatid lizards.

Male-female expression imbalance of X-linked genes is widespread across phrynosomatid lizards, with female-biased expression observed in both ancestral and neo-X regions.

• Why it matters: Understanding sex chromosome evolution and dosage compensation mechanisms is crucial because they influence gene expression balance between sexes, yet many species show incomplete compensation, leaving gaps in knowledge.
• What they did: The study analyzed gene expression in Sceloporus undulatus and ten other phrynosomatid species across different tissues and developmental stages, revealing persistent female-biased expression on X chromosomes regardless of age or tissue.
• The result: Findings suggest that male-female expression imbalance is conserved in this family, with overexpression in females for ancestral X regions and underexpression in males for neo-X regions, indicating widespread and complex dosage regulation.